The basis of this circuit is the HA2400 released at the time. The circuit is from a Radio Electronics magazine from March 1980. The power supply must be symmetrical at 15 V.
This circuit was taken from recent English documentation. The circuit uses a 500 uA microammeter as an...
Found in Popular Electronics from the 90s, this circuit uses a reed switch on the rails as a...
This filter for scratch and rumble noises that occur on turntables was found in the February 1995...